Last week, techies at the code-sharing site GitHub received a treat when former NASA intern Chris Garry uploaded the source code for the Apollo 11 Guidance Computer, reports Keith Collins at Quartz. The Apollo Guidance Computer (AGC) was installed on board and served the lunar module that eventually reached the moon in July, 1969.
The source code was written by the MIT Instrumentation Lab with input from computer engineering pioneer Margaret Hamilton. And soon after the data was posted, the internet went to town dissecting every line. Collins reports that the code is written in an assembly program language that is gobbledygook to many programmers today. But the Apollo engineer's comments within the code, which explain what each section does, are a time capsule of 60s geek culture.
Users at Reddit have gleefully sifted through the comments eating up the in-jokes and pop culture references. The master ignition routine, for example, is called "
BURN, BABY, BURN," the slogan of the popular DJ Magnificent Montague that became a chant during the 1965 Watts Riots in LA. Another section of code was dubbed "
TRASHY LITTLE SUBROUTINES."
PINBALL_GAME_BUTTONS_AND_LIGHTS.s," the coder inserts some lines of Shakespeare.
# THE FOLLOWING QUOTATION IS PROVIDED THROUGH THE COURTESY OF THE AUTHORS.
# "IT WILL BE PROVED TO THY FACE THAT THOU HAST MEN ABOUT THEE THAT
# USUALLY TALK OF A NOUN AND A VERB, AND SUCH ABOMINABLE WORDS AS NO
# CHRISTIAN EAR CAN ENDURE TO HEAR."
# HENRY 6, ACT 2, SCENE 4
It’s not known why, exactly, The Bard appears in the Apollo code, but Reddit users speculate it's because the AGC code was input as two digit numbers, one called the noun, the other the verb.
Another line reads, "
HONI SOIT QUI MAL Y PENSE," the motto of the Order of the Garter that means, “shamed be he who thinks evil of it.” In other words, one coder was warning others not to bash or make fun of his code.
“It's humbling to see that the folks who wrote the code that took us to the moon are basically just like me and my coworkers,” writes Reddit user rooktakesqueen.
The code has been on the internet for years, Collins reports, first as scanned photocopies of paper printouts that MIT put online and later by Google. But the GitHub upload has renewed interest in the Apollo code.
The original AGC had just 3840 bytes of data and weight 70.1 pounds. A virtual simulation of the original shows just how old school the computer was compared to today’s high-powered machines. But, at the time, work on the AGC was a huge step forward in software development.
Even so, the significance of the code has not stopped modern coders from flagging two dozen typos and other problems that need fixing at GitHub.